Rotary offset-printing press.



H. PEARC-E & T. R. G. PARKER.

ROTARY OFFSET PRINTING PRESS. APPLICATION FILED NOV. I2, I9I3.

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Patented Feb. 13,1917.

6 SHEETS-SHEET 2- H. PEARCE & T. R. G. PARKER. ROTARY OFFSET PRINTING PRESS.

APPLICATION FILED Nov. 12, |913.

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ROTARY OFFSET PRINTING PRESS.

APPLICATION FILED Nov. 12, |913.

1,215,404. Patented Feb. 13,1917.

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ROTARY OFFSET PRINTING PRESS.

APPLlcATIoN FIL-En Nov. 12, 191s.

1,215,404. lIltemeed Feb.13,1917.

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H. PEARCE &`T. R. G. PARKER.`

ROTARY OFFSETy PRINTING PRESS. APPLICATION FILED NOVJZ. 1913.

1,21 5,404. Patented Reb. 13, 191?.

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HERBERT PEARCE AND THOMAS ROBERT GILLETT PARKER, k0F BROADHEATH, ENC-r- IIAND, ASSIGNORS TO LINOTYPE ND MACHINERY LIMITED, OF LONDON, ENGLAND.

ROTARY OFFSET-PRINTING PRESS.

Specification. of Letters Patent.

Patented Feb. 13, 1917.

T0 all whom t may concern:

Be it known that we, HERBERT PRARCRA and THOMAS ROBERT GILLETT PARKER. subjects of the King of the United Kingdom of Great Britain and Ireland, and residing at Linotype and Machinery Works, Broadheath, in the county of Chester, England, have invented new and useful Improvements in Rotary Oifset-Printing Presses, of which the following is a specification.

This invention relates to improvements in that class of rotary offset printing press which is adapted to print alternatively two color or perfector work, and it has, among its principal objects, to provide a' press having two plate cylinders, two transfer cylinders each of the latter in operative contact with one of the plate cylinders, and a single impression cylinder coperating with both of the transfer cylinders, the said five cylinders being arranged with their axes in planes forming approximately an equilateral triangle, those of the two plate cylinders being in a plane below, and that of the impression cylinder being in a plane above, the axes of the transfer cylinders.

Hitherto, in printing presses of the abovenamed class, considerable .trouble has been experienced owing to the difficulty with which access could be had to the various cylinders thereof for inspection, cleaning and other purposes, and a special advantage secured by the present invention is the elimination or minimizing of the said difficulties, this result being attained by the aforesaid relative arrangement of the cylindersv and their location .at such height in the press that they are all well within the view of the operator when he is standing on the iioor level.

The invention-is also advantageously applicable to rotary perfecting presses.

In the accompanying drawings which are to be taken as 'part of this specification and read therewith z- Figure 1is the left hand part and Fig. 1a the right hand part of an elevation, as viewed from the gear side, of a press according to the present invention;

Fig. 2 is a plan of part of the mechanism of the press shown in Fig. 1, with a certain member thereof,--to witthe yoke 38 represented -diagrammatically ;-A

Fig. 3 is. an elevation, as seen from the underside ofF-ig. 2, with some of the parts omitted;

Fig. 4L is an' elevation, as seen from the left-hand side of Fig. 2;

Figs. 5 and 6 are diagrammatic views illustrative of the operation of the press when producing multi-color printing, and

Figs. 7, 8 and 9 are diagrammatic views illustrative of the operation of the same press when producing perfected printing.

The several figures are drawn to different scales and throughout these gures like reference numerals are used to indicate like or corresponding parts. I

In the form of the press represented there Iare provided two plate cylinders 1, 2 both of the same diameter, supported in bearings 3, 4; respectively, in the two side frames 5 of the press; of these frames only that at the gear side of the press is shown in the drawings. In peripheral contact with each of the plate cylinders 1, 2, there is provided a 'rubberor equivalently-clothed transfer cylinder 6, 7 respectively, the diameter of each of which is half that of the respective plate cylinder 1, 2.

The two transfer cylinders 6, 7 are in operative contact with a single impression cylinder 8, the diameter of which is also half that of each of the plate cylinders 1, 2, or, in other words, of the same diameter as each of the transfer cylinders G, 7.

The'transfer cylinders 6, 7, are supported lin bearings 9, 10, respectively, in the side frames 5, and the shaft 11 of the impression cylinder 8, is journaled in eccentric bushes or bearings 12 which are. capable of being turned angularly in bearing boxes 13 which are themselves capable of being raised and lowered in vertical guides l"in the side frames 5. y

The axes of the plate cylinders 1, 2, and impression cylinder 8 are situated in planes forming approximately an equilateral triangle, that of the impression cylinder being uppermost and at the apex of such triangle, in a vertical plane midway between the axes of the plate cylinders, which last named axes are in the same horizontal plane, while the axes of the transfer cylinders 6, 7, are

situated slightly above or outside the two reversely inclined planes in which are situated the axes of the impression cylinder 8 and the respective plate cylinder 1 or 2.

Under each of the bearing boxes 13 there is provided a vhelical spring 14, (one of which is shown in dotted lines in Fig. 1a) exerting a constant lifting effort'on the impression cylinder 8, and attached by a pivot 15. to each such bearing box, is the upper end of a short eccentric rod or link 16 whose lower end encircles an eccentric 17 fast to a shaft 13 capable of being rocked about a stationary axis, and having fast thereon. a lever arm 19. To the swinging end of the lever arm 19 is pivoted the upper end of a preferably adjustable rod or link 2O whose lower end is similarly connected to a crank arm 21 fast to a rocking shaft 22.

The rocking shaft 22, receivesits rocking motion from a toothed sector lever 23 oscillated about a stationary pivot 24 by a groovcd cam 25 preferably on the end of the plate cylinder 1, this sector lever 23 gearing with a toothed segment 26 mounted loosely upon the rocking shaft 22. The toothed segment 26 is Lprovided with two oppositely directed abutments 27, 28 with the former of which are capable of being engaged two separate pawls 29 and 30a, and with the latter of which is capable of being engaged a pawl 30. The pawls 30 and 30il are integral with each other and constitute a double-ended pawil, and this double-ended pawl and the pawl 29 are respectively pivoted on lever arms 32 and 31 mounted on, but normally free from the rocking shaft 22. In Fig. 4, the pawl 30'6L is immediately in front of, and practically obscures from view, the pawl. 29.

The bosses of the last-named lever arms 31, 32, are provided with clutch members or faces 33, 34 respectively, with which can be engaged corresponding clutch members or faces 35, 36 axially slidable on the rocking shaft 22 but splined thereto by feathers 37, these two clutch members 35, being rigidly secured togeth .3 as by a yoke or bridge 3S, so that when say, as is illustrated in Figs. 2 `and 3, the clutch member 35 is moved into engagement with the corresponding clutch member 33, the clutch lmember 36 is correspondingly moved out of engagement with the clutch member 34 and when, reversely, the clutch member 36 is engaged with 34, then is disengaged from 33; there is an intermediate position in which both of the clutch members and 36 are simultaneously disengaged from the respective members 33, 34.

@n the rocking shaft 22 vthere is also loosely pivoted a cam 39, see particularly Fig. 4, which, through an arm 40 integral.

therewith, and well-known link and lever devices 41, is connected to a pedal 42 capable of being depressed and released by the ogerator, this cam 39, being so arranged that when the pedal 42 is depressed, it (the cam) will be moved angularly about the rocking shaft 22, into the-pathbof an antifriction roller 43 pivoted on the beforementioned pawl 29, so that when the roller reaches the said cani, the pawl 29 will, against the action of its controlling spring 44, Fi g. 4, be moved out of engagement with the abutment 27 on the toothed segment 26.

rilhe pedal 42 is connected, in well-known manner, with a grooved cam 45 which engages with an anti-friction roller 46 `on the before described double-ended pawl 30, 30a, this cam serving to move the end 30 of the said pawl out of Land into engagement with the abutment 23 on the toothed segment 26, the pawl being engaged when the pedal 42 is depressed, and disengaged when under the influence of a spring 47, the pedal. is elevated.

It tooth 4S fast to the before-mentioned lever arm 31 extends laterally from that arm into the path of the abutment 2S and, when engaged by the said abutment, serves to turn that arm clockwise and thereby effect a lifting of the impression cylinder S off impression.

Each of the before described eccentric bushes 12 has fast thereto or integral therewith, a lever arm 49 to which is pivoted the upper end of a preferably adjustable eccentric rod 50 whose lower end embraces an eccentric 51 fast on a second rocking shaft 52. rihis rocking shaft 52 has loose upon it, a spur pinion 53 which meshes with the lower end of a toothed sector lever 54 pivoted upon a stationary stud 55 and on whose upper end is pivoted an anti-friction roller engaging vith a grooved cam 56 on the end of the plate cylinder 2. The pinion is provided on one side with a clutch face 57, Fig. 2, with which is capable of engaging a movable clutch member 58, splined to thc rocking shaft 52 by feathers 59, and embraced by a collar 60 fitting loosely in. an annular groove in the said member. rJill'iis collar 60, is connected by a link 61 (shown in dotted lines in Figs. 2 and 4) to one arm of a two-armed lever 62; the other arm of this lever is swiveled to a collar 63, loosely engaging an annular .groove in the beforedescribed clutch member 36 and, through this member, and the yoke 38, .it is also connected to the clutch member The lever 62 is fast to a short vertical shaft 6-1- which is free to be turned about its vertical axis in a stationary bracket bearing 65 fast to the adjacentside frame 5, the said shaft, for this purpose, hav-ing secured thereto a lever handle '66, Figs. .2, 3 and 4, which extends through the adjacent side frame to a position in which it can be conveniently manipulated by the operator;

When the before-described press is to produce two impressions on the same side of a sheet, asin multi-color work, a sheet is fed from the feed board 67, to the impression cylinder 8 at every alternate rotation of the latter, and each such sheet receives two successive superimposed impressions one from each of the two transfer cylinders 7, 6 (which have previously received the impressions from the respective plate cylin-4 ders 2, l) the sheet subsequently being delivered by a chain or other delivery mechanism 68, on to the delivery board 69, either printed side up or down.

The operations of the before-described press will now be described by reference to the diagrams shown in Figs. 5 to 9 in which the various arrows indicate the directions of rotation of the different cylinders.

In these diagrams 1a and 2a indicate the plate or printing surfaces on the plate cylinders l, 2 respectively; Ga and 7a the rubber or equivalent transfer blankets of the transfer cylinders 6, y7 respectively; 6b and 7 b the reel rods by which the said blankets are stretched around the respective supporting surfaces of the cylinders 6, 7 g 8a the grippers which secure the sheets to the impression surface 8b of the impression cylinder 8; 67 the feed board, and 68 a chain or other delivery which is capable of delivering the sheets printed side up or down on to the delivery board 69.

When the press is to produce two impressions on the same side of the sheets, as in multi-color work, the before-described clutch mechanism is inthe condition of adjustment in which it is shown in Figs. 2 and 3, so that of the two rocking shafts 22, 52, only 22 will, for the time-being, be rocked, and the lever arm 32 and double-ended pawl 30, will remain inoperative. The pedal 42, being then in its raised position, the

cam 39 will be in the position in which it is shown in Fig. 4, so that the pa-wl 29 will remain in the path of the abutment 27 and consequently the shaft 22 will be continuously rocked anti-clockwise by that pawl to lower the impression cylinder, and clockwise by the tooth 48 to raise the said cylinder. 1f now, the pedal 42 is depressed, the cam 39 is brought into the path of the roller 43 and effects the movement of the pawl 29 out of the path of the abutment 27, and simultaneously therewith the. grooved cam 45 is raised so as to -move the pawls 30 and 30a respectively into and out of engagement with the abutments 28, 27, with the result that, at the neXt succeeding clockwise turn of the shaft 22, effected through the engagement of the abutment 28 with the tooth 48 and the mutual engagement of the clutch members 33, 35,

-the lever arm 21 will also be moved clocksuch sheet at each alternate rotation of the impression cylinder 8. Through the rocking shaft 22, Figs. 1 to 4, the impression cylinder is, at that juncture raised off impression as represented in Fig. 5, and is maintained in that condition until the grippers 8 arrive at theposition in which they are shown in Fig. 6, so that throughout that period no impression is transmitted by the transfer cylinders 6, 7. `When the grippers 8a have arrived at or about the position in which they are shown in Fig. 6, the shaft 22 has rocked anti-clockwise and brought the cylinder 8 down on impression or in printing position as shown in Figs. 1 and 1, so that the sheet will receive first an impression from the transfer cylinder 7 and then another impression superimposed or not on the first one, from the transfer' cylinder 6. The last-named printing relationship of the impression cylinder 8 relatively to the transfer cylinders (3, 7 is maintained until the following or tail end of the impression surface 8" has passed out of printing contact with the transfer surface 6, at which juncture the shaft 22 is rocked clockwise and the impression cylinder is thereby again raised off impression. 'A

When the grippers 8a are presented above the axis of the impression cylinder 8, they are opened to release the sheet which is then seized, in well-known manner, by the delivery mechanism 68 which afterward drops it on to the'delivery board 69. At the next succeeding rotation of the impression cylinder 8, a sheet is engaged by the grippers 8 and the j ust-described sequence of operations is repeated.

When the press is to be used for perfecting, the impression cylinder 8 is clothed with an offset blanket, represented in Figs. 7, 8 and 9 by the curved dotted line 70, and the lever handle 66 is moved yleftward e., upward in Fig. 2,) so as to disengage the clutch face 35 from 33 and engage the clutch faces 36 and 58 with 34 and 57 respectively and thereby bring both of the rocking shafts 22 and 52 into operation.

When the press is being thus used for perfecting, the impression cylinder 8, requires to be raised oif impression only in the event of failure in the feeding of a sheet to it and this is effected by depressing the pedal 42 as previously described in connection with theV multi-color printing, and although the impression cylinder 8 will still continue to be rocked through the eccentric 5l, it will not come into contact with the transfer cylinders 6, 7 until after the pedal is next released. Vith the press thus operating, the offset blanket 70, at'every alternate rotation of the impression cylinder 8, receives a resti-ansferred impression from the blanket 7a during a period at which, through the rocking shaft 52, the impression cyiinder 8 is, as shown in Fig. 7 out of printing contact with the transfer cylinder 6. fit the next ensuing rotation of the impression cylinder 8, a sheet is fed to the gripper-s 8 and through the rocking shaft 52, the impression cylinder 8 is moved out of, and into contact with the transfer cylinders 7 and 6 respectively, so that when the sheet passes betweenthe cylinders G and S it receives impressions from both of them on its respectively opposite sides. After the tail of the sheet has passed from between the cylinders 6 and 8,

Y the rocking shaft 22 eifects the raising of the impression cylinder 8 as shown in Fig. 9, and, prior to this raising of the cylinder, the sheet has been engaged by the grippers of the delivery mechanism 68. Just before, the grippers 8, during this `delivering rotation reach the line joining the aXes of the cylinders 7, 8, the cylinder 8 is lowered into contact with the cylinder 7, as shown in Fig. 7, so as to receive a re-transferred impression from the last-named cylinder and thereby commence a sequence of operations similar to that previously described.

7l and 7 2 represent respectively the damping and inking mechanisms which may be of any desired construction, and between which there is provided sufficient space to admit of free access being had to the respective printing plates for cleaning or other purposes.

Having described our invention, we decl are that whatwe claim and desire to secure by Letters Patent is:-

1. A rotary offset printing press having in combination two plate cylinders, two transfer cylinders each .in operative contact with one of the plate cylinders, and a single impression cylinder cooperating with both the transfer cylinders, the five said cylinders being arranged with their axes in planes forming substantially an equilateral triangle, those of the two plate cylinders being in a plane below and that of the impression cylinder being in a plane above the axes of' the transfer cylinders, and means for tri pping and untripping the impression cylin der with reference to either both transfer cylinders simultaneously or either cylinder independently of .the other.

2. i rotary offset printing press having in combination two plate cylinders, two transfer cylinders each of the latter in -operative contact with one of the plate cylinders, anda single impression cylinder coiperating with both of the transfer cylinders, the live plate, transfer and impressioncylinders being arranged with their axes in planes forming substantially an equilateral triangle, those of the two plate lcylinders being in a plane below, and that of the impression cylinder bei-ng in a plane above, the axes of the transfer cylinders, and ymeans operative to move the impression cylinder oif impression with the two transfer cylinders either in alternation or simultaneously.

1n witness whereof we have `hereunto set out hands in the presence of two witnesses.

HERBERT PEARCE. THOMAS ROBERT GILLETT PARKER.

ldi-tnesses ERNALD SIMPSON MosELEY, MALcoLM SMETHURST.

Copies o this patent may be obtained for five cents each, by .addressing the Commissioner of Patents,

Washington, D. C. 

